<Source: Revised from Hougang Care Centre (Singapore mental rehab centre) Courses.>
Strangers are people you do not know. Turn them into Acquaintances.
Acquaintances are half-way friends. A bit stranger & a bit friend. Turn them into Friends.
Friends are people you know very well. Keep them as friends.
Friends Of Utility. Friends that can help each other.
Friends Of Pleasure. Friends that can have funs & pleasure with.
Friends Of Lasting. True friends that can be with.